First, in Guatemala Claro is the service mark of Telecommunicaciones de Guatemala S.A., also known as TELGUA. But, we call them Claro so we can use expressions such as “Claro que no”. Those of us who have had the opportunity to deal with Claro in multiple countries tend to have low expectations.
I could list an assortment of issues (that’s new-speak for problems) with them but I wanted to just address one that appears to have a solution. The problem is not receiving their bill. I don’t know if this is a country-wide problem but it appears to happen frequently in Panajachel. While you can just go to their office on Calle Santander and pay by just telling them your phone number, I actually needed a utility bill in my name (as proof of address).
Unlike some less successful interactions I have had with them, the client service folks seem to be used to this problem and will print out a new bill for you. Not multi-cowered like the one that gets lost all so often but with all the barcodes and such so that it looks official.
If you just want to pay your bill, you can do it on their web site with (only) a Visa credit card.